Steam generator



K. A. MAYR STEAM GENERATOR Jul 14, 1931;

-2 Sheets-Sheet 1 7 Filed Oct. 4, 1927 r 388 onowo owowowo July 14; 1931.

4, 1927 2 Sheets-Sheet 2 344mm ot Patented July 14, 1931 UNITED STATES PATENT OFFICE KARL A. MAYR, OF NEW YORK, N. Y., ASSIGNOR TO SIEMENS-SGHU'CKERTWERKE AK'IIENGESELLSGHAFT, 0F SIEMENSSTADT, NEAR BERLIN, GERMANY, A CORPORA- TION OF GERMANY STEAM ennnna'ron Application filed October 4, 1927. Serial No. 223,856.

This invention relates to improvements in steam generators and more particularly to improvements in steam generators of the flash yp One object of the present invention resides in the provision of a construction. which will provide for high and maximum output in a minimum space at maximum eflicienc-y.

Another object is to provide a construction in which heat losses by radiation, are reduced to a minimum by providing a construction having a minimum outside heat dissipating surface. a

Another object resides in the provision of a combustion chamber which is best adapted for proper combustion.

Another object resides in a novel arrangement of heat absorbing elements to the general and that radiant heat and heat from the hot'gases is more effectively absorbed than heretofore. r

A further object resides in the provision of a construction which obviates dead corners so that all hot flowing gases are eifective in giving up heat and all parts of the apparatus act efliciently in absorbing heat.

A. further object of the present invention resides in the provision of. a construction which will be simple to assemble and dismantle and which provides for free and independent expansion of the parts when in use.

A further object resides in the provision of a novel preheater for incoming air which is concentric with the heat absorbing structure and combustion chamber wherebycompactness is secured and whereby an air jacket is provided for the highly heated parts.

Further objects and advantages will be hereinafter set forth in the accompanymg specification and claims and shown in the drawings, which shows by way of illustratlon what I now consider to be one and a perfect embodiment of my invention.

In the drawings Figure 1 represents a central vertical sectional view of the steam generator.

In more detail, the steam generator is suitably supported upon a base support 20. 21 designates a substantially cylidrical combustion chamber. This combustion chamber is slightly conical for improving combustion action and for facilitating disassembling of the various parts. The upper head of this combustion chamber generally designated 22, forms the subject matter of a separate application, Serial No. 223,857, filed October 4:, 1927, and this part of the apparatus is adapted to suitably mix finely divided fuel and the air for combustion and to direct the burning mass downwardly into chamber 21 with a turbulent and whirling motion.

The various heat absorbing elements will now be described. 22 is a spiral tubular coil suitably supported on the base 20 and having its lower portion formed of loops generally designated 23, to provide open passages. from the combustion chamber in an outer direction as indicated by the arrows 24.

The incoming feed water is supplied through an inlet pipe such as 25. Just outside coil 22 is a tapered cylindrical shell 26 which secures its support by the frictional engagement of the coil 22' which is within it. It may be also suitably supported by spot welding if this is desired. The water entering coil 22 receives the intense radiant heat in the combustion chamber 21 and is heated thereby and the coil 22 is further heated by the hot gases which sweep over its surface. From coil 22 an outlet pipe 27 leads outwardly and downwardly and connects to a mud collector or trap 28. From the outlet of this mud collector 28 a pipe 29 leads to a spiral'coil 30 which is disposed in back of the lower portion of shell 26 to aid in protect ing said shell against the effects of the still highly heated gases. From the top of this coil 30 a connection 31 leads to the inner of concentric coil 32. This is likewise a spiral and from this coil the water or steam, as the case may be, is led to the next outer coil 32 at the bottom and through that coil to the next and outermost coil at the top as indicated by arrows 35 and 36. From the bottom of the outermost coil 32 a pipe 37 leads to the throttling or reducing valve generally designated 38 and from this valve a further pi e39 leads to the bottom inner coil of a tu e nest generally designated 40. The circulation through this tube nest is generally the same as for the nest 32, viz, up on the inside, then down, then up, then down and "then up in the outer coil 40. From the top of the outer coil 40 a pipe 41 leads downwardly completely out of the apparatus and eventually extends to the high pressure steam consumer generally designated 42. From this consumer the steam flows into a suitable in-. termediate receiver 43 and thence it returns through a pipe 44 to the outer of a nest of spiral concentric coils 45. This nest constitutes a reheater for the steam. The steam after passing them flows again out of the apparatus through pipe 46 to the low pressure consumer.

It will be understood that the reheater can be dispensed with if desired and when such reheater is dispensed with the coil nests 32 and 40 can be arranged with a lesser number' of concentric convolutions and can occupy the space previously occupied by the reheater. In this case the annular diameter could be somewhat decreased.

Outside the tube nests 40, 32 and 45, preheater boxes are provided. The inner walls of these preheater boxes define the outer wall of the heat absorbing chamber for the tube nests 40, 32 and 45. These .preheater boxes are best shown in Fig. 2 and comprise an inner curved wall portion 50 and an outer wall portion 51 and-connecting plate portions 52 suitably flanged and fastened to shell plates 50 and 51.' To connect adjacent heater boxes together and to rigidly fasten the same to the base casting 20, each heater box may be rovided with an outer flange portion 53 suitably fastened thereto and between adjacent flanges 53, a plate 54 is provided which extends down into cooperat'on with the base 20. Suitable connecting bots 55 afiord means for connecting adjacent box 's to each other and to the plate 54.

The preheater boxes have disposed within them vertically extending pipes 56 which at their lower and upper ends are supported by header plates 57 and 58 respectively. The tube spacing of the tubes 56 is such that the flow of air which isto be preheated is substantially equalized at inner, outer and intermediate points in the preheater chambers. This may be effected by disposing the outer tubes with the same center to center. spacing which is provided for those tubes which are relatively closer to the inner wall ofthe preheater as shown in the drawings, Figs. 2 and 3. In other words, the disposition of the flows upwardly around the preheater tubes.

Suitable bafiles 65 may be provided in the preheater boxes to avoid thejormation of dead corners, to increase theturbulence of the air, and to increase the velocity of air in order to improve the heat transfer conditions. 'Arrow 66 indicates the flow of the air as it leaves the preheater. The preheated air goes into an annular chamber 67 and thence to an air chamber 68 from which it is admitted into the combustion chamber in the manner described in my copending ap lication.

It will-be understoo that the ot gases from the combustion chamber traverse first the tube nest 40 thence tube nests 32 and 45 and afterwards pass into a header 69 disposed above the upper tube plate 58. From this header 69 the hot gases pass downwardly within the tubes 56 and eventually pass out of the apparatus at.a duct 70, which may be connected with any suitable exhaust fan.

It is contemplated that the particular steam generator herein described is to operate with oil fuel, although it issuitable for other fuels. When oil fuel is utilized, there are times when oil may collect in the bottom of the-apparatus. To provide for draining out such oil and to prevent coke from choking the outlet pipe for such oil, I provide a tapered bottom refractory plate 71 havin a central opening 72 closed by a manhole %3.

This manhole is provided with an oil drain" tube 74 having a flap valve 7 5 on its end which opens automatically if the oil level rises in tube 74. To prevent clogging by coke I preferabl provide a mushroom shaped cover 76 which cover has a series of oil drain grooves 77 in the bottom thereof which lead to the open end of pipe 74.

What I claim is:

1. A steam generator comprisin in combination a combustion chamber 0 tapered cylindrical contour'which inwardly tapers towards the bottom thereof, and heat absorbing tubes of corresponding contour, other heat absorbing tubes without said first mentioned tubes, said contour of the combustion chamber and of the first mentioned tubes facilitating assembly and disassembly of the tubes by permitting upward withdrawalof the first mentioned tubes with the other tubes in position. F

2. A steam generator comprising in combination with a base, a combustion chamber,

of heat absorbing means therein comprising a tube section disposed at and forming the wall of the combustion chamber, and a plurality of openly spaced loops connected to said tube section, said loops supporting the gforesaid tube section from the aforesaid ase.

3. A steam generator comprising in combination with a combustion chamber, of a shell therearound and heat absorbing tubes frictionally engaging the shell and disposed to receive direct radiant heat from the combustion chamber, means for supporting the tubes independently of the shell, said frictional engagement of the tubes and the shell affording a support for the shell from the supported tubes. 1

4. steam generator comprising a centrally disposed combustion chamber, a heat absorbing chamber surrounding the central combustion chamber, a partition dividing the said chambers and comprising a plurality of heat absorbing coils, other heat absorbing conduits relatively openly spaced and adapted to be traversed by the hot gases enroute from the combustion chamber to the heat absorbing chamber, and other coils disposed in the heat absorbing chamber, and means connecting the various coils to permit a liquid to flow first through the relatively openly spaced conduits thence through the partition forming coils and thence throu h the heat absorbing coils in the heat absorbin g chamber.

5. A steam generator including a combustion chamber, a heat absorbing chamber, and a plurality of groups of tubes in the absorption chamber, and air preheating means including in combination therewith, a sup-.

porting casting, means for supporting the plurality of tubes in the chamber from said casting, said air pre-heater comprising detachable sections about the tubes, said sections also receiving vertical. support from said casting.

6. A steam generator including means forming a combustion chamber, a heat absorbing chamber therearound and an air prelleilter around the heat absorbing chamber, said air pre-heater comprising in combination, a plurality of indepegdentlydetachable air pre-heater boxesmich are disposed around the aforesaid heat absorbing chamber.

7. A steam generator including a combustion chamber, a heat absorbing chamber therearound and an air pre-heater around 'the heat absorbing chamber, said air preheater comprising a plurality of independently detachable air pre-heater boxes, a supporting base, and supplemental means for supporting the aforesaid air pre-heater boxes from said base.

8.- A steam generator including means forming a combustion chamber, heat absorbing means therearound and an air jacket completely around the generator through which tube section, said loops supporting said tubesection from the aforesaid base, means for admitting cooling Water first to the open loops, and means for thereafter passing the water from the open loops into the tube section.

10. A steam generator comprising in combination with a base, a combustion chamber, of heat absorbing means therein comprising a tube section disposed at and forming the Wall of the combustion chamber, a plurality of openly spaced loops connected to said tube section, a heat absorbing chamber Without the combustion chamber, said loops supporting said tube section from the aforesaid base and said loops by the openings therebetween also afiording an entrance passage for the hot gases from the combustion chamber into the heat absorbing chamber.

In testimony whereof I hereto'aifix my signature.

' KARL A. MAYR. 

